Symantec updates

Symantec is adding only one-two new definitions every day !!!!
In those condition hourly updates (like kaspersky) will be a nonsense !
But ,with a small database , compared with others they still recive very good results on comparative tests (among the best).
Can anyone explain this ?

Symantec uses some "generic" names such as Backdoor.Trojan, IRC.Trojan, Trojan Horse, Construction Kit, etc. There may be, for example, ten thousand signatures mapped to one name such as the Backdoor.Trojan. Thus there is no way to tell how many distinct signatures that exist in their database. Kaspersky and other vendors assign UNIQUE names to malware so there is closer to a one-to-one correspondence between the number of signatures and the number of names. All that you can "see" on Symantec's list are new NAMES but there is no way to know how many new Signatures they have added from one update to the next.